On Wed, 20 Oct 2004 09:59:58 +0100 Dave wrote: DS> > but the twist is that the value of DS> > the variables are computed from a common source that is costly to access. DS> DS> OK - so the 'shared_handler' routine caches this value in some way, DS> and uses that cached value to service incoming requests, only recomputing DS> it when the cached value gets "too old" (however you want to define this). DS> DS> You should be able to use the 'cache' helper to implement this.
The other option I've used before is to use the data list of the agent request info pointer. The same agent request pointer is passed to all handlers for teh varbinds in a given request. In each handler, try to extract the value from the list. If it isn't there, get the value and put it in the list for any other instances of the handler. If you have a shared handler for different instances, you need to make sure you use a unique key for the datalist. When the request is completed, the data list will be destroyed, and the free function (if any) will be called. i.e. caching this way only works for the lifetime of the current request. To cache for longer, the cache helper or any proprietary caching would be needed. DS> [The cache helper] was originally designed to slot into the handler chain DS> and be invoked automatically, but I believe Robert has done some work to DS> make it useable "standalone". No, I still use it in the context of an injected handler, though you just made me realize that in some cases, it shouldn't be (when the cache is refreshed periodically, instead of only on demand (i.e. incoming request)). -- Robert Story; NET-SNMP Junkie <http://www.net-snmp.org/> <irc://irc.freenode.net/#net-snmp> Archive: <http://sourceforge.net/mailarchive/forum.php?forum=net-snmp-coders> You are lost in a twisty maze of little standards, all different. ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ Net-snmp-coders mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/net-snmp-coders
